WO2023007513A1

WO2023007513A1 - A detachable device for filtering air and a pre-processed filter

Info

Publication number: WO2023007513A1
Application number: PCT/IN2022/050670
Authority: WO
Inventors: Sumit Kumar Verma
Original assignee: Sumit Kumar Verma
Priority date: 2021-07-26
Filing date: 2022-07-25
Publication date: 2023-02-02

Abstract

A detachable filter assembly (45) for mounting on a conventional air circulation equipment (e.g. ceiling fan) that includes a frame (1) with slots to mount it on fan blade (80) and a provision to secure an air filter medium (40). The frame (1) of the device (45) has a blade mount slot formed therein that is dimensioned to slidably engage a ceiling fan blade (80). The filter can be secured at least at two slots on the frame (1) to keep it attached to the frame (1). When the fan blade (80) rotates, the device (45) with the frame (1) and the filter media (40) secured on it, moves along with it, and filters the medium (100) it is moving in. The proposed invention also relates to a replaceable pre- processed filter (40) that can be used in any air filtering device (45).

Description

Title : A DETACHABLE DEVICE FOR FILTERING AIR AND A PRE-PROCESSED FILTER

DESCRIPTION

The complete specification derives priority from earlier provisional application No. 202111033594, dated 26 July 2021 and provisional application No. 202211032408 dated 06 June 2022, on the same/similar invention.

FIELD OF INVENTION AND USE OF INVENTION

The present invention relates to a detachable device for filtering air to be mounted on the arm of an air circulation equipment such as a fan or a blower. The present invention also relates to a pre-prepared or pre-processed filter medium to be housed inside the device for air filtration.

The invention relates to a medium (such as air) cleaning devices and components. But in particular to a simple, detachable device with means of retrofitting one or more blades of the fan and with a removable filter to extract particles and pathogens of predetermined size from a medium through which fan blades rotate.

BACKGROUND AND PRIOR ART OF THE INVENTION

The ceiling fan comes into contact with a quantity of particles along with the air. These particles can be dust, pathogens, smoke or industrial residue, among others. These particles pose health hazard to humans in many situations. The air being moved by fan can keep these particles airborne for a very long time in the absence of a means of trapping and filtering these particles out from the air.

Hence, there is a need for a device and a method that can be used with existing fans to substantially eliminate accumulated dust and particulate from the air, or at least lessen their particulate count in the air being circulated. There is also a need for a device that can make air relatively safer to breath. The present invention addresses these needs. Table 1 - List of Prior Arts

Reference is taken from the above Table (Table 1 - List of Prior Arts).

The invention disclosed in US4753573 and US4840650 can be used only with rigid filters or self-supporting filters which do not deform under the load such as when fan blade(s) are rotating. This requirement limits the type of filters which can be used with the embodiment. The invention provides support to filter from one side only and does not provide any support from the opposite side. Further due to this limitation flexible filter media and for non-woven filter which can also filter out various types of pathogens from the air cannot be used in the invention. The US4753573 further suggest the use of a channel member in one of the embodiments, which would create additional resistance for blades and would slow them down further. US4840650 also limits the filter media to be woven. It also suggests to use air channelling means which are not required as the moving blades would already be drawing air into the filter. These would create additional resistance for fan blades and would negatively impact the rotations per minute (RPM) of the fan. Additionally, it also requires a grid like front stop or screen at the front side of the filter which is unnecessary because the air going from front to back would push the filter media backwards so no full support in this direction was needed. As a result, this poor design adds an additional non-productive resistance for the air passing though the filter and which would reduce the speed of fan blades.

US5562412 requires a slot be made in the fan blade. As an alternative to slot in a fan blade it also suggests to use fastener to attach the filter to fan blade. In both of the cases the fan blade would be permanently deformed. Further Velcro method which is intended to be used to attach filter to the fan blade will not be able hold the filter on fan blade for a very long duration due to the cross-sectional size of the filter which is said to be 20 square inch.

It is anticipated that a filter this size will reduce the fan speed to an unusable level. An experiment to study the impact of size of filter on fan speed was conducted on a three blade ceiling fan with around 316 RPM. It was observed that a filter of the size 12.5cm X 3.25cm (6.3 square inch) on all blades of a three blade can reduce the RPM around 10-15 percent .. Therefore, as suggested in US5532412, a filter with 20 square inch cross section, on each of the fan blade would reduce the fan speed so much that the fan would become unusable. This test has been shared as an example of one of the embodiments 45 of our invention and should not be treated limiting.

Further, US7052524 provides a filter media of approximately 40 cm (16 inch) by 12.5 cm (5 inch) front supported by a backing framework. The 80 square inch (16 inch X 5 inch) filter size would produce an even more resistance for air than the filter mentioned in US5562412. Further, a backing framework made from soft iron mesh or even with plastic or wood increase the weight on the fan blade. Further, the mesh would also generate additional undesirable friction or resistance. The additional weight and friction would reduce speed of fan further. The backing framework further requires an edge protector to cover the cut wire ends. This would increase the cost of making and put additional weight on the fan blade.

In US7367777B2 similar to US4753573, the filter needs to be self supporting as it is secured at one side only. Fan mount and filter mount creates additional undesired resistant for the air due to their relatively larger cross sectional area.

Further many other prior arts US4422824, US5341565, WO1997044624A1, CN1189667C, US20070079588A1, US20080047241A1 and WO2016200047 A 1 require fan blades to be permanently modified or use different type of blades. US6790004 and US9599116 requires the air to go over the filter media and not through it. This method is relatively less efficient as most of the common filter medias are designed to filter the medium going through them. Therefore, these common filter media cannot be used in US6790004 and US9599116. Further, WO 1994008142 A 1 requires the fan to be covered with the filter embodiment which would be relatively costlier in terms of making and installation both.

It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application. Similarly, a problem mentioned in the background section, should not be assumed to have been previously recognised in prior art.

OBJECT OF THE INVENTION

A principal object of the present invention is to provide an air filtering device which can be attached to one or more arms of the air circulation equipment like fan, blower etc. to remove dust and other unwanted particles from the air as the blade rotates. Another object is to provide an inexpensive and easy to install and replaceable means such as a frame for attaching an air filter to a fan blade without permanently modifying the fan blade Yet another object is to provide a device consisting of a relatively simple, inexpensive, easy to install and replaceable filtering means to the frame attached/mounted to the fan blade(s)

Another object is to provide a relatively light weight apparatus which also presents relatively lesser resistance to air flow and creating relatively lesser adverse impact on the speed of the fan.

Another object of the proposed invention is to provide a replaceable pre-prepared filter medium.

Yet another object of the proposed invention is to provide a pre-prepared filter capable of filtering particulate matter and microbes.

These and other objects and advantages of the present invention will become apparent to those skilled in the art after considering the following detailed specification which discloses several representative embodiments of the present air filter in association with ceiling fans as shown in the accompanying drawings. SUMMARY OF THE INVENTION

The proposed invention relates to a detachable device for filtering air which consists of a frame with a means to attach the device on to one or more arms of an air circulation equipment such as a fan or blower and a means of filtration wherein the frame is a hollow structure comprising of at least one slot like structure to attach the device to the arm of the air circulation equipment; a provision to house or secure the means of filtration and an optional provision to couple the device more securely to the arm of the air circulation equipment.

In another embodiment of the device, the frame has multiple slot like structures of varying sizes to attach to the arm of varying thickness of air circulation equipment. In an embodiment, the structure of the device is decided on the combination of area for allowing air to enter (draw in the air) and the type of filter such that that reduction in the RPM of air circulating equipment remains less than 20 percent of the original speed before mounting the device. In yet another embodiment of the device, the frame is rectangular in shape with four walls namely left, right , upper and lower, open front side and open back side creating a hollow cavity to house the means of filtration, and which has

- the left wall and right wall have one or more parallel slits along the width of the frame, to attach to the arm of the air circulation equipment;

- the means of filtration is mounted across the upper wall and lower wall optionally through a slit provided on either or both walls;

- the upper and lower walls optionally have a notched rectangular slit to house any pre-processed replaceable filter across the left and right arms on the upper and lower walls.

In another embodiment, the frame has a circular or oval cross section with at least one slot like structure to attach the device to the arm of the air circulation equipment; a provision to house the means of filtration ; and an optional provision to couple the device more securely to the arm of the air circulation equipment. In another embodiment, the device comprising of a frame with at least one means to attach the device on to one or more arms of an air circulation equipment and a means of filtration wherein the frame is a hollow structure comprising of at least one slot like structure to attach the device to the arm of the air circulation equipment; a provision to house the means of filtration; and an optional provision to couple the device more securely to the arm of the air circulation equipment; the means of filtration comprises of one or more layers of filter media, housed inside or secured on the frame; optionally through at least one filter media slot on the frame; and secured on the frame by a means to hold through friction.

The proposed invention also relates to a replaceable pre-processed filter for the detachable device for filtering air, having one or more layers of woven or non- woven filter media and wherein the filter media is selected from HEPA fabric filter, Wattman filter paper, HEPA filters made of plastic or borosilicate glass fibres, light-metal fine mesh filter, fiberglass filter; pliable filters made of nylon nanoparticles, polyester fabric, cotton fabric, muslin cloth , fabric, washable material or any combination thereof; the filter optionally consists of one or more additional charcoal layer impregnated between two or more layers of the filter media; the filter optionally consists of layers of materials having scented or anti microbial properties between one or more layers of the filter media; and the filter consists of one or more sleeve like structure on one or more sides for attaching the filter to the walls of the frame through the notched slit to fit into the frame.

In another embodiment of the device, the width of the filter media is in the range of 75-100 mm for a device of width 75-85 mm and height 45-55 mm.

In an embodiment the filter is made by cutting smaller rectangular pieces of length 180-230 mm and width of 75-85 mm from a larger sheet or roll, and then stitches at least at one place by folding it over itself.

The proposed invention also relates to a frame for a detachable device for filtering air, wherein the frame is rectangular in shape with four walls namely left, right, upper and lower, open front side and open back side creating a hollow cavity to house the means of filtration, and wherein, the left wall and right wall have one or more slits along the width of the frame, to attach to the arm of the air circulation equipment; at least one slit is provided on either or both the upper wall and lower wall to mount the means of filtration ;the upper and lower walls optionally have an opening to slide any pre -processed replaceable filter across the left and right arms on the upper and lower walls.

BRIEF DESCRIPTION OF DRAWINGS

The figures 1-7 derive priority from Provisional application No. 202111033594, dated 26 July 2021 and figures 8-10 derive priority from provisional application No. 202211032408 dated 06 June 2022.

The present invention is best understood in conjunction with the accompanying drawing figures in which like elements are identified by similar reference numerals and wherein: Figure 1: Shows an embodiment of the proposed invention from front side with a filter media slot on upper and bottom wall each, and a slot on right wall to be mounted on fan blade.

Figure 2: Shows the embodiment shown in figure 1 mounted on a ceiling fan. Figure 3 : Shows an embodiment of the proposed invention where both left and right wall have one slot each to be mounted on fan blade.

Figure 4: Shows an embodiment of the proposed invention as viewed from the back side.

Figure 5: Shows an embodiment of the proposed invention similar to figure 4 with an alternative filter media slot to secure filter media on frame.

Figure 6: Shows another embodiment of the proposed invention with two holes each on upper and lower walls to attach / secure filter media sheet.

Figure 7: Shows an embodiment of the proposed invention similar to shown in figure 6 but with additional flange or project part to place an adhesive /attaching mechanism.

Figure 8: Shows an embodiment (45) of the proposed invention with multiple fan blade slots (35) at both side walls left (5) and right (10), and filter slots (25), at upper wall (15) and lower wall (20) with an opening (26). It also shows an enlarged view of the opening (26). Figure 9: Shows a filter media (40) folded over itself from its two sides and sticked / welded /sewed etc. at line (41) at both sides to keep the overlapping layers together.

Figure 10: Shows a filter media (40) folded in over itself at the centre and sticked / welded /sewed etc. at line (41) at far side edges of the layers from centre to keep them together.

DETAILED DESCRIPTION OF THE INVENTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” “secured”, fixed”, “attached” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. It will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

The term ‘filter media’, 'filter means', ‘filter’ and ‘means of filtration’ are used alternatively in the same concept of a material capable of filtering a medium (air) and made of one or more layers of the material capable of filtration.

The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

STRUCTURE Figure 1 shows an embodiment (45) of the proposed invention having a frame / housing (1) to secure filter media on, and to be mounted on a fan blade (not shown). It has four walls with predetermined dimensions. The frame (1) can be made of plastic, metal, wood, composite etc sheet or wire or filament or any other material which can satisfactorily hold the filter (40) and remain satisfactorily mounted on fan blade(s) (80). The frame (1) has a front side (60) from where the air enters and a back side (65) from where the air exits. The direction of air has also been shown with arrow B. When looked from the front (60) the four walls have been referred as left (5), right (10), upper (15) and lower wall (20). Left wall (5) and right (10) have an optional slant shape at lower back side. Any of the four walls of the frame (1) can also be of rectangular or of any other shape.

A slot (25) has been cut on each of the upper (15) and lower (20) walls. The slot (25) shown in this embodiment is a through hole type in which the material has been completely removed from the slot (25) making a window like feature on upper wall (15) and lower wall (20). The right wall (10) has another slot (35) to mount the embodiment (45) to mount on fan blade (80). A filter media (40) has been folded over and below each of the upper wall (15) and lower wall (20). At upper side the folding of filter media (40) has been done in a way that the two layers of the filter media sheet (40) goes above and below of the upper wall (15) like the bread slices are placed in a sandwich. The upper wall (15) remains between both of these layers as filler. It has been ensured that both of the layers of filter media (40) goes slightly beyond the slot (25) from front (60) to back (65). Since the slot (25) is through hole it allows both layers of filter media (40) above and below it to come in direct contact. Both layers on upper wall (15) have been spot welded (can also be glued / stappled / stitched or secured in any other suitable manner) on the two ends (70) of the slot (25) to keep this side of the filter media (40) secured at upper wall (15). Similarly, the other side of the filter media has been secured with welding spots (70) on slot (25) on lower wall (20).

Figure 2 shows the embodiment (45) also shown in figure 1 mounted on a fan blade (80) of a fan (75). The embodiment (45) has been shown to be mounted on the leading edge of a fan blade (80), but it can also be mounted on more than one fan blades (80). It is also possible to mount more than one embodiment (45) on a single fan blade (80). Further, it is also possible to mount the embodiment (45) on any other edge of fan blade (80). A part of fan blade which is covered by the embodiment (45) has been shown with broken line / dotted line. As mentioned in the description of the figure (1) the embodiment (45) has a slot (35) on its right wall (10). The slot (35) has been used to mount embodiment (45) on the fan blade (80). A neck (85) connecting fan blade (80) to the fan motor (95) has been shown in figure 2. Width of neck (85) is smaller than the fan blade (80). That is why the leading edge of fan blade (80) is slightly ahead of the leading edge of neck (85). This difference make it appear like a shoulder (90) at both sides of neck (85) on fan blade (80). The gap between fan motor (95) and shoulder (90) has been used to accommodate the left wall (5) of the embodiment (45) as shown in the figure 2. Therefore, the left wall (5) does not have a slot (35) similar to right wall (10).

The embodiment (45) shown in figure 3 is similar to shown in figure 1 and 2 but it additionally has a slot (35) on its left wall (5) as well. The additional slot (35) on left wall (5) would help when the fan (75) is of a design where the neck (85) is either completely not present or the gap between motor (95) and shoulder (90) cannot be used to accommodate left wall (5). Also, when it is desired to mount the embodiment 45 on fan blade 80 using both walls (left (5) and right (10)) a slot (35) on each of the left (5) and right wall (10) would be required. It is also possible that the frame (1) has multiple slots (35) of different sizes, so that it can be mounted on the blade (80) of various thicknesses and styles.

The figure 4 shows the embodiment (45) shown in the figure 3 from the back side (65). The rotating blades will apply centrifugal force on embodiment (45). Optionally an adhesive strips / attaching mechanism (50) (shown with broken lines) can be placed below the lower side of the upper wall (15) or any other wall to provide additional support to the embodiment (45) against centrifugal force. The adhesive /adhesive strips (50) will keep the predetermined side of the embodiment (45) affixed at the surface of the fan blade (80). The additional support will prevent embodiment (45) from sliding over and falling off the fan blade, when the slot (35) is not have tight fit on fan blade.

The figure 5 shows an alternative filter media slot(s) (27) optionally used at the place of slot (25). The slot has been shown to be rectangular but can also be of any other shape, provided it can be used to secure the filter media (40) on the frame (1).

The figure 6 shows an embodiment (45) similar to the embodiments shown in the previous figures. In contrast, it has two holes (30) each on upper (15) and lower wall (20) to secure filter media (40). The filter media (40) has been secured in each of the holes (30) with welding spot (70).

The figure 7 shows another embodiment of the proposed invention similar to figure 6 but with additional flange / projected / extended part (55) of upper wall (15). An adhesive tape (50) has been applied on the lower side of flange (50). The adhesive 50 affixed on the lower surface of the flange (55) has its second side affixed over the surface of the fan blade (80). When this embodiment (45) (shown in figure 7) will be mounted on the fan blade (80). The tape (50) will provide support to the embodiment (45) against the centrifugal force on embodiment (45).

The figure 8 shows another embodiment of the proposed invention where multiple fan blade slots (35) of different sizes have been placed on left wall (5) and right wall (10) of frame 1. This enables the same frame 1 to be used on the fan blade(s) (80) of different sizes and styles. Further figure 9 and 10 shows two different types of pre-prepared or pre-processed filter media (40). The pre-prepared here means that a user can place or mount the filter (40) on frame 1 directly without any further step such as gluing, stappling, spot welding, etc. at his end to media (40) on the frame 1 when fan blade (80) is rotating.

The filter media shown in the figure 9 has two smaller sleeves. The filter media shown in figure 10 has one single larger sleeve. The sleeves of the filter media of figure 9 needs to be slightly larger than the front part of the frame (1). The front part is the portion between the front edge and parallel edge of the slot (25) nearest to it. There is also an opening (26) which makes the slot (25) directly accessible from the front side of upper (15) and lower wall (20). This opening (26) can be used to place or put on media (40) on the arms created on the front size of the upper wall

(15) (arm 16 and 17) and lower wall (20) (arm 21 and 22), through the opening (26).

The sleeve size (inner radius if circularly spread) in filter (40) being slightly larger than the cross section of the arm (16, 17, 21 and 22) enables the sleeve to be placed on the slot (25) (as shown in figure 1, 3 and 10) by sliding the one side of the sleeves opening from the opening (26) onto either of the left (16) or right (17) upper arms. The other side of the sleeve would be slidden on to the other side right (17) or left

(16) upper arms. The ends of the sleeve would be stretched to the ends of the slot (25) which is nearest to the side walls (5) and (10), to spread the filter media to maximum.

The same would again be repeated with the sleeve at other side of the filter media. The other sleeve of the filter media will be placed on the left lower arm (21) and right lower arm (22). There by making the placement of the filter (40) on frame (1) similar shown in figure 1 and figure 3.

The filter media (40) shown in figure 10 can also be placed on the frame (1) by the similar process shown for the filter media (40) shown in the figure 9 previously. Both of the filter media (40) shown in figure 9 and 10 can also be placed on frame (1) by placing it first on either set of lower arms (21) and (22) or upper arms (16) and (17) and thereafter on the other set of the arms. The figure 10 also shows how the filter media (40) would look like when it would be placed / put on / fixed at frame (1) shown in figure 8 from side (from the right side of frame 1).

The combination and design of the frame (1) shown in figure 8 and medias (40) shown in figure 9 and/or figure 10, will keep media (40) on the frame (1) when the blades are rotating without any further preparation. This makes the filter media (40) very easily to be mounted, unmounted and replicable on frame (1) at users’ end.

OPERATION

With reference to the figure 1 and figure 2, when the fan (75) is switched on the fan blades (80) would start rotating. Then a predetermined volume of air would pass through the filter (45) in the direction shown by arrow (B). The air would enter from the entry (60) and would exit from the exit (65). The filter media (40) placed in between the path of the air would remove undesirable particles and pathogens from it. It can also optionally have a feature to remove odours or predetermined gases through chemicals or active agents. It can also have an optional feature of adding fragrances to the air passing through it. One or more optional features can be used along with the feature of removing undesirable particles and / or pathogens from air.

When the fan blades rotates a centrifugal force would become applicable on the embodiment (45). As a result of the same, the embodiment (45) would like to slip away from the fan blade (80) in the direction of arrow (A). Since a part of left wall (5) is supported against the shoulder (90). The shoulder (90) would keep the embodiment (45) at its position and would not allow it to go into the direction of the arrow (A).

With reference to the embodiments shown in figure 3, 4 and 5 the slot (35) on left wall (5) would also be used like slot (35) on right wall (10) to mount the embodiment (45) on fan blade (80). In case the slot (35) on left (5) and right (10) have been designed to tightly fit on the fan blade (80) then they would prevent the embodiment (45) to move in the direction of arrow (A) and fall off the fan blade (80). Further, in some cases the slots (35) may not have a tight fit to the fan blade (80). Then, as shown in figure 4, an additional provision to secure the device onto the fan blade, such as an adhesive tape (50) is used which prevents it from falling off the blade due to centrifugal force. As an alternative to an adhesive tape (50) or along with, one or more clips can also be used to keep the frame 1 mounted on the fan blade (80).

Similar to the embodiment shown in figure 4, in the embodiment shown in figure 7 also, the adhesive (50) provides the support to the embodiment (45) against the centrifugal force (shown with arrow A).

The variations shown of filter (40) in figure 9 and figure 10 can be made separately and can be directly used with the frame (1) shown in the figure 8. The resulting embodiments (45) can be used similar to the ones shown earlier. Since the frame (1) shown in figure 8 has multiple slots (35) of different sizes. During the operation it would be mounted on a fan blade (80) with the suitable slot (35) as per as per the thickness and design of a fan blade (80). The suitable slot (35) will give a desired tight fit on the fan blade (80), so as, that when the blade (80) rotates/moves the frame (1) along with the filter (40) on it will be kept at the fan blade.

The frame (1) can have any shape or size depending on the requirement based on the size of the arm of air circulation equipment i.e. the fan blade (80), as long as there is a provision/means for attaching it to the arm (80) and there is at least one filter media (40) that can be accommodated on or inside or both the said frame to carry out filtration of air when the fan blade is moving. It is possible to make the frame (1) using 1 (straight, curved, or circular etc.), 2 or 3 wall(s) at the place of 4 as shown in the embodiments of figure 1 to 7. The frame (1) can also be made from sheet or wire or filament or from a combination of thereof to achieve the same result of keeping the filter media (40) attached to the blade (80). It is also possible to have slot (35) of different sizes as shown in figure 8 to be on the right wall (10) only similar to the embodiment show in figure 1.

Another can be with an embodiment (45) where filter (40) can be secured to the frame (1) using a means of holding through friction (71).

Further optionally the frame (1) can be tied to a fan blade or to its neck through a thread, a rubber band, an elastic, a zip tie (also known as hose tie, self-locking ties, self-locking cable, cable ties etc.) or similar flexible means. The description and drawings provided only illustrate embodiments of the present invention and should not be construed in limiting the scope of the invention.

Further, even though the embodiments 45 largely discuss about air filtration through a fan but the proposed invention can also be satisfactorily used with other type of fans and propellers for filtering multiple types of mediums such as but not limited to air, water, oil etc. Table 2: LIST OF PARTS AND FEATURES

ADVANTAGES:

1. The proposed device is lightweight, detachable, economical, and efficient solution for filtering air that can be attached to the fan blade.

2. The proposed device is detachable with easily replaceable filters for easy maintenance.

3. The proposed device has been designed to have lesser adverse impact on the speed of the fan blade.

4. The proposed invention allows non self-sporting, flexible fabric like high efficiency filters to be economically used as filter that effectively filters dust particles and microbes. 5. The proposed device & filter can be made of any suitable material and can be manufactured in any shape and size depending on the requirement.

Claims

We Claim:

1. A detachable device (45) for filtering air, comprising of a frame (1) with at least one means (35) to attach the device on to one or more arms (80) of an air circulation equipment (75) and a means of filtration (40); wherein

-the frame ( 1 ) is a hollow structure comprising of at least one slot like structure (35) to attach the device (45) to the arm (80) of the air circulation equipment (75); a provision to house or secure the means of filtration (40); and an optional provision (50) to couple the device (45) more securely to the arm (80) of the air circulation equipment (75);

-the means of filtration (40) comprises of one or more layers (M) of filter media,

- housed inside or secured on the frame (1); optionally through at least one filter media slot (25) on the frame (1); and

- secured to the frame (1) by means of a fastening medium (70).

2. The detachable device (45) for filtering air, as claimed in claim 1, wherein the frame (1) has multiple slots like structures (35) of varying sizes to attach to the arm (80) of varying thickness of air circulation equipment (75).

3. The detachable device (45) for filtering air, as claimed in claim 1, wherein the structure of the device (45) is decided on the combination of :

- area (60) for allowing air to enter; and

- type of filter (40); such that reduction in RPM of air circulating equipment (75) remains less than 20 percent of the original speed before mounting the device (45).

4. The detachable device (45) for filtering air, as claimed in claim 1, wherein the frame is rectangular in shape with four walls namely left (5), right (10), upper (15) and lower (20), open front side (60) and open back side (65) creating a hollow cavity to house the means of filtration (40), and wherein the left wall (5) and right wall (10) have one or more slits (35) along the width of the frame, to attach to the arm (80) of the air circulation equipment (75); the means of filtration (40) is mounted across the upper wall (15) and lower wall (20) optionally through a slit (25, 27) provided on either or both walls. the upper (15) and lower (20) walls optionally have an opening (26) to slide over any pre -processed replaceable filter across the left (16, 21) and right arms (17,22) on the upper (15) and lower walls (20).

5. The detachable device (45) for filtering air, as claimed in claim 1, wherein the frame has a circular or oval cross section and wherein at least one slot like structure (35) to attach the device (45) to the arm (80) of the air circulation equipment (75); a provision to house the means of filtration (40); and an optional provision (50) to couple the device (45) more securely to the arm (80) of the air circulation equipment (75).

6. The detachable device (45) for filtering air, as claimed in claim 1, comprising of a frame (1) with at least one means (35) to attach the device (45) on to one or more arms (80) of an air circulation equipment (75) and a means of filtration (40); wherein

-the frame ( 1 ) is a hollow structure comprising of at least one slot like structure (35) to attach the device (45) to the arm (80) of the air circulation equipment (75); a provision to house the means of filtration (40); and an optional provision (50) to couple the device (45) more securely to the arm (80) of the air circulation equipment (75);

- secured on the frame by a means to hold through friction (71).

7. A replaceable pre-processed filter (40) for the detachable device (45) for filtering air, comprising of one or more layers (M) of woven or non-woven filter media and wherein the filter media is selected from HEPA fabric filter, Wattman filter paper, HEPA filters made of plastic or borosilicate glass fibres, light-metal fine mesh filter, fiberglass filter; pliable filters made of nylon nanoparticles, polyester fabric, cotton fabric, muslin cloth , fabric, washable material or any combination thereof; the filter optionally consists of one or more additional charcoal layer impregnated between two or more layers of the filter media; the filter optionally consists of layers of materials having scented or anti-microbial properties between one or more layers of the filter media; the filter consists of one or more sleeve like structure (42, 43) on one or more sides for attaching the filter to the walls of the frame (1) through an opening (26) to fit into the frame (1).

8. The replaceable pre- processed filter (40) as claimed in claim 7, wherein the width of the filter media is in the range of 75-100 mm for a device (45) of width 75-85 mm and height 45-55 mm.

9. The replaceable pre-processed filter (40) as claimed in claim 7, wherein the filter (40) is made by cutting smaller rectangular pieces of length 180-230 mm and width of 75-85 mm from a larger sheet or roll, and then stitching it (41) at least at one place by folding it over itself.

10. A frame (1) for a detachable device (45) for filtering air, wherein the frame (1) is rectangular in shape with four walls namely left (5), right (10), upper (15) and lower (20), open front side (60) and open back side (65) creating a hollow cavity to house a means of filtration (40), and wherein the left wall (5) and right wall (10) have one or more slits (35) along the width of the frame(l), to attach to the arm (80) of the air circulation equipment (75); - at least one slit (25, 27) is provided on either or both the upper wall (15) and lower wall (20) to mount the means of filtration (40); the upper (15) and lower (20) walls have an opening (26) to slide over any pre -processed replaceable filter (40) across the left (16, 21) and right arms (17,22) on the upper (15) and lower walls (20).